<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>Bootstrap列组合</title>
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"/>
    <link rel="stylesheet" href="css/bootstrap.min.css"/>
    <style>
        body{
            margin-top: 20px;
        }
        .row div{
            outline: 1px solid red;
        }
    </style>
</head>
<body>
<div class="container">
    <div class="row">
      
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
        <div class="col-md-1">col-md-1</div>
    </div>
    <br/>
    <div class="row">
        <div class="col-md-4">col-md-4</div>
        <div class="col-md-8">col-md-8</div>
    </div>
    <br/>
    <div class="row">
        <div class="col-md-4">col-md-4</div>
        <div class="col-md-4">col-md-4</div>
        <div class="col-md-4">col-md-4</div>
    </div>
</div>

</body>
</html>